Transesterificação enzimática de óleo de soja por lipase presente no concentrado bruto do fungo Colletotrichum gloeosporioides: uma abordagem alternativa ao uso de lipases comerciais

• Ano de defesa: 2012
• Autor(a) principal: Paulo Antônio Sette de Abril
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: transesterificação enzimática; Colletotrichum gloeosporioides; biodiesel; Química orgânica; Biodiesel; Catalisadores
• Link de acesso: http://hdl.handle.net/1843/SFSA-8UJVJY

In this work, a crude lipase-containing preparation, obtained from filamentous fungus Colletotrichum gloeosporioides, was employed as catalyst in the transesterification of vegetable oils, with the aim of producing biodiesel enzymatically. The preparation was obtained by submerged fermentation, under orbital shaking, of C. gloeosporioides. The fermented broth was concentrated by ultrafiltration, trough a cellulose acetate membrane with 10 kDa cut-off weight and lyophilized. The powder obtained showed a lipase activity of 9.75 U/mg. Refined soybean oil and methanol were used in the transesterifications. These were carried out in 125 mL flasks under orbital shaking. The parameters of enzyme concentration, alcohol to oil molar ratio, amount of added water, stepwise addition of methanol and the addition of hexane were studied. The conversion of triglycerides to methyl esters was analyzed by gas chromatography, coupled to mass spectrometry, using selective ion monitoring, focusing on ions at m/z 74 and 87. A maximum yield of 2.13% m/m in methyl esters was obtained with an enzyme concentration of 30.6 U/mL, alcohol to oil molar ratio of 4:1, amount of water added 45.9% m/m, related to oil mass, and addition of 2 mL of hexane. The studies suggest that, to increase the yields, it is necessary to obtain a preparation with greater lipase activity